Language bindings, KDE thumbnails, yapf compare, in-memory encoding

- yapf_encode() / yapf_free_buffer(): encode to memory; yapf_save uses it
- yapf.c also compiles as C++
- `yapf compare`: size and decode speed of the original format vs YAPF,
  with a lossless check
- bindings with tested examples: C++ (header-only), C# (P/Invoke),
  Rust (crate, builds the C code), Go (cgo), Java (FFM API, Java 22+),
  Zig (@cImport), LuaJIT (FFI), TypeScript types for the JS port;
  Python now encodes in memory
- docs/LANGUAGES.md and examples/ with measured results
- KDE Dolphin thumbnail plugin (KF6, CMake)
- README: honest status for Photoshop / VS Code / Figma (not run in the
  apps yet) and macOS (cross-compiled only), platform table

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

extensions/kde/CMakeLists.txt

@@ -0,0 +1,26 @@
+# YAPF thumbnails for KDE Dolphin (KF6 KIO thumbnail plugin).
+#   cmake -B build -DCMAKE_BUILD_TYPE=Release
+#   cmake --build build
+#   sudo cmake --install build        (or see README.md for a per-user install)
+cmake_minimum_required(VERSION 3.16)
+project(yapfthumbnail LANGUAGES C CXX)
+
+find_package(ECM 6.0 REQUIRED NO_MODULE)
+set(CMAKE_MODULE_PATH ${ECM_MODULE_PATH})
+include(KDEInstallDirs)
+include(KDECMakeSettings)
+include(KDECompilerSettings NO_POLICY_SCOPE)
+
+find_package(Qt6 6.5 REQUIRED COMPONENTS Core Gui)
+find_package(KF6 6.0 REQUIRED COMPONENTS KIO)
+find_package(Threads REQUIRED)
+
+kcoreaddons_add_plugin(yapfthumbnail
+    SOURCES yapfthumbnail.cpp ../../yapf.c
+    INSTALL_NAMESPACE "kf6/thumbcreator")
+set_source_files_properties(../../yapf.c PROPERTIES LANGUAGE C)
+target_include_directories(yapfthumbnail PRIVATE ../..)
+target_link_libraries(yapfthumbnail PRIVATE KF6::KIOGui Qt6::Gui Threads::Threads)
+
+# Register the image/x-yapf file type so Dolphin recognises .yapf files.
+install(FILES ../linux/yapf-mime.xml DESTINATION ${KDE_INSTALL_MIMEDIR} RENAME yapf.xml)